Expansible linkage

ABSTRACT

The present disclosure provides an improved expansible linkage comprising a plurality pairs of link elements, each pair of link elements consisting of a lower and an upper link element connected to each other at their central portions to form an Xshaped link unit. The lower link element is shaped in the form of a sheath having an opening at the center of its upper surface. The upper link element has a pair of projections which are located in positions adapted to be freely turnable in the opening of the lower link element, and wire spring means are inserted with said lower link element and engaging with the projections of said upper link element.

United States Patent [72] inventor Tetsuzo Shibuya 46 Sanchome. .\1iya ko iiman Nakadori.

Miyakojima, Osaka. Japan [21] Appl. No. 770,944 [22] Filed Oct. 28, 1968 {45] Patented June 15, 1971 [32] Priority Oct.3l, 1967 [33] Japan [3 l] 42/70028 [54] EXPANSIBLE LINKAGE 4 Claims, 9 Drawing Figs. [52] U.S. Cl 59/79, 63/5 [51] Int. Cl F16g 13/24 [50] Field ofSearch ..59/79,79.5; 224/44, 4.8, 4.2, 4.1 1; 63/5 [56] References Cited UNITED STATES PATENTS 881,925 3/1908 Holbrook 59/79 2,433,766 12/1947 Kubice 59/79 Primary ExaminerCharles W. Lanham Assistant Examiner-Gene P. Crosby Attorney-Morgan, Finnegan, Durham & Pine ABSTRACT: The present disclosure provides an improved expansible linkage comprising a plurality pairs of link elements, each pair of link elements consisting of a lower and an upper link element connected to each other at their central portions to form an X-shaped link unit. The lower link element is shaped in the form of a sheath having am opening at the center of its upper surface. The upper link element has a pair of projections which are located in positions adapted to be freely turnable in the opening of the lower link element, and wire spring means are inserted with said lower link element and engaging with the projections of said upper link element.

PATENTEDJUNISIHTI 3584-;456

SHEET 1 OF 2 INVENTOR 720020 Jkmm A PATENTEB JUN 1 5 WI SHEET 2 [1F 2 INVENTOR w um UMM w 1 FM 75% EXPANSIBLE LINKAGE BACKGROUND OF THE INVENTION There are known expansible linkage which comprises a plurality of pairs of links, each pair of link being pivotally connected to each other at their centers in superimposed relationship to form an X-shaped link unit and also pivotally connected to adjacent pairs of link of the same form and construction. The expansible linkage of this type are popular in the bracelets for Wristwatches.

Because of the complexity of the internal mechanisms, these linkages, however, are extremely thick and not very attractive in appearance. Therefore, when they are used as bracelets for Wristwatches, they damage the shirt sleeves due to their thickness and since they are centrally provided with mechanical pivotal elements which tend to destroy especially, they will be damaged if such elements slip off. Thus previously known expansible linkages have several disadvantages in point of ornament and function and therefore are not yet fully satisfactory.

A primary object of the present invention is to provide novel and useful expansible linkages in which the above disadvantages can be avoided.

Another object of the invention is to provide an expansible linkage having an extremely simplified structure without any central mechanical pivotal element.

A further objection of the invention is to provide an expansible band which is capable of performing a safe action of ex pansion and contraction.

I SUMMARY OF THE INVENTION The present invention relates to the improvements in the expansible linkage for use in articles of jewelry such as bracelets, bands, belts and the like.

According to the present invention, there is provided an expansible linkage for article of jewelry comprising a plurality of pairs of link elements, each pair of link elements consisting of a lower and an upper link element connected to each other at their centers in superimposed relationship to form an X- shaped link unit, and means for pivotally connecting each pair of link elements to adjacent pairs of link elements of the same form and construction characterized in that said lower link element is shaped in the form of a sheath having an opening at the central portion of its upper surface, while said upper link element is shaped in the form of an elongated plate adapted to cover the upper surface of said lower element, said upper link element having a pair of projections which are located in positions adapted to be freely turnable in the opening of said lower link element, respectively, and that wire spring means are enclosed within said lower link element and engage with said projections of said upper link element, respectively, whereby to provide a connection of said lower and upper link elements at their center portions and to exert a force against each upper and lower link element and tend to swing them on said connection to bring them into substantial alignment.

In this construction, projections of the upper link element are located near the opposite elongated side edges of said element, respectively.

Also, wire spring means are substantially U-shaped and one end of each spring means is engaged with and retained by the projections of said upper link element while the other end of the spring bears against the side of said lower link element. In this specification, wire spring means may comprise both one wire of preferably S-shape and a pair of wires. Further, each of the projections has a lateral extension at its free end.

There is also provided an expansible linkage according to the present invention, in which projections are formed on the central portions of the elongated edges of the upper link element and the elongated sides of the lower link element are cut away at their respective portions corresponding to said projections of the upper link element.

Further, wire spring means are substantially of arch shape and engage at their respective apex portions with said projection of the upper link element.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an expansible linkage according to the present invention shown in a contracted position;

FIG. 2 is a view similar to FIG. 1 but showing the linkage in an expanded position;

FIG. 3 is a greatly enlarged, perspective view of an embodiment of the lower link element according to the invention;

FIG. 4 is a enlarged perspective view of another embodiment of the lower link element;

FIG. 5 is a enlarged perspective view of an embodiment of the upper link element;

FIG. 6 is a enlarged perspective view of another embodiment of the upper element;

FIG. 7 is an enlarged plan view of an expansible linkage according to the invention shown in an expanded position, the linkage being partly broken away at an upper link element thereof to show the internal structure;

FIG. 8 is a view similar to FIG. 6 in case wire spring means are in the form of a U-shape; and

FIG. 9 is a enlarged perspective fragmentary view of one element showing the relation between. the upper link element and wire springs means in a contracted position, a portion of the lower link element being shown broken away.

The foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT The expansible linkage of the present invention according to the preferred and illustrative embodiment of the invention comprises plurality of pairs of link elements, each pair of link elements consisting of a lower link element 31 and an upper link element 32.

The lower link element 31 is shaped in the form of a sheath having an opening 33 at the central portion of its upper surface, and the opening 33 is preferably defined by a pair of concave arcually shaped edges 34 but it may be of a complete circular shape.

The upper link element 32, as sown in FIG. 5, is shaped in the form of an elongated plate adapted to cover the upper surface of the lower link element 31 and has a pair of projections 35. These projections 35 are, preferably, located near the opposite elongated side edges of the upper link element 32, respectively, and spaced apart from each other by with respect to the center, preferably, adapted to engage said arcual edges 34 of the opening of the lower link element 31, respectively.

The expansible linkage according to the invention also includes spring means, which are preferably a pair of wire springs 36 enclosed within the lower link element 31 and adapted to engage with the projections 35 of the upper link element 32, respectively, whereby to provide a connection of the lower and upper link elements at their central portions.

Now, two elements 31 and 32 are superimposed at their central portions, one on top of the other and, at the same time, wire springs are inserted within the lower link element 31 adapted to engage with the projections 35 of the upper link element 32 so that a pair of the X-shaped link units is formed. A plurality of such link elements are connected in series, wherein for example each pair of link elements is pivotally connected to adjacent pairs of link elements by means of projections 37 and corresponding holes 38 such as in conventional linkages, thereby providing an expansible linkage as shown in FIG. 1 (contracted position) FIG 2 and FIG. 7 (expanded position).

In this construction, wire springs 36 exert a force against each upper and lower link element and tend to swing them on their central connection to bring them into substantial alignment. When the lower and upper link elements are turned X- wise to expand the linkage, therefore, the contraction is effected by utilizing the repelling force resulting from the deformation of wire springs 36, so that the linkage can be contracted extremely easily and effectively.

According to one embodiment of the invention, wire springs 36 may be substantially of U-shape and one end of each spring is engaged with and retained by the projection of the upper link element while the other end of the spring bears against the side of the lower link element as shown in FIG. 8. In such type of structure, the function and effectiveness are, of course, not at all different from those in the preceding structure described above.

The invention also comprehends a structure for firm clamping of wire springs 36 with respect to the projections 35 of the upper link element.

When the lower and upper elements and turned X-wise to expand the linkage, the area of the neck portion 41 of the outer 35 contacted by wire springs 36 move from the inner surface to the lateral surface or, in some cases, to the outer surface and often become disengaged from the top portion 42 of the projections 35. In this case, if some vertical force is applied to the wire springs 36, the latter becomes disengaged from the projections 35, thus failing to perform the contracting function.

To prevent this, as shown in FIG. 9, lateral extension 43 may be formed at the free end of the top portion 42 of each projection 35 so as to cover the wire springs 36 even at the maximum angle of turning, or wire springs 36 may be substantially of arch shape and engage at their respective apex portions with the projections of upper link element as shown in FIG. 9 so as to clasp the neck 41 of the projections 35 at the maximum angle of turning, or both of these measures may be used in combination, thereby preventing the disengagement.

According to another embodiment of the invention, projections 35 are formed on the central portions 39 of the elongated edges of the upper link element 32 as shown in FIG. 6 and elongated sides 40 of the lower link element 31 are cut away at their respective portions corresponding to said projections 35 of the upper link element as in FIG. 4.

That is to say, in expansible linkage of the present invention, projections 35 serve to maintain the function of connecting the lower and upper elements by pressing and clasping of the wire spring 36. These functions are, also, attained by the projections 39 as shown in F 10. 6. In this case, the elongated sides of the lower link element must be cut away at portions corresponding to the projections so as to be freely turnable at their central portions with respect to each other.

As described above, according to the present expansible linkage, since the connection between the lower and upper elements is effected by the wire springs inserted therein, there is no need of providing pivot or similar mechanical connections such as in the conventional linkages. Further, the expansion of the linkage is effected while pressing the wire springs by the projections formed on the upper element, and the contraction is effected by utilizing the repelling force resulting from the deformation of the wire springs, so that the linkage can be contracted easily and effectively.

Also, the present expansible linkage is very simple in structure and can be decreased in thickness and has a beautiful appearance and satisfactory expansibility. Further, since this construction makes it easy to take off a pair or pairs of links from the linkage, the linkage is advantageous in repair.

While the device is herein shown as embodied in a preferred form of construction, it is to be understood that various modifications may be made in structure and arrangement of its parts without departing from the spirit or scope of the invention.

What I claim is:

1. An expansible linkage for articles of jewelry such as bracelets, bands, belts and the like, comprising a plurality of pairs of link elements, each pair of link elements consisting of a lower andan up er link element pivotally connected to each other at their cen ers ll'l superimposed relationshtp to form an X-shaped link unit, and means for pivotally connecting each pair of link elements to adjacent pairs of link elements of the same form and construction, in that said lower link element is shaped in the form of a sheath having an opening at the central portion of its upper surface, while said upper link element is shaped in the form of an elongated plate adapted to cover the upper surface of said lower element, said upper link element having a pair of projections which enter into said opening of said lower link element; that spring means are enclosed within said lower link element and engage with said projections of said upper link element, so as to exert a force against each upper nd lower link element to tend to swing them on said connection to bring them into substantial alignment; and that said projections are formed on the central portions of the elongated edges 0 the upper link element and the elongated sides of the lower link element are cut away at their respective portions corresponding to said projections of said upper link element.

2. An expansible linkage as defined in Claim 1, in which said spring means comprises a pair of substantially U-shaped wire members, one end of each of said wire members being engaged with and retained by one of said projections of said upper link element while the other end thereof bears against the side of said lower link element.

3. An expansible linkage as defined in claim 2, in which each of said projections of said upper link element has a lateral extension at its free end.

4. An expansible linkage as defined in Claim 1, in which said spring means comprises a pair of substantially arch-shaped wire members which engage at their respective apex portions with said projections of said upper link element. 

1. An expansible linkage for articles of jewelry such as bracelets, bands, belts and the like, comprising a plurality of pairs of link elements, each pair of link elements consisting of a lower and an upper link element pivotally connected to each other at their centers in superimposed relationship to form an Xshaped link unit, and means for pivotally connecting each pair of link elements to adjacent pairs of link elements of the same form and construction, in that said lower link element is shaped in the form of a sheath having an opening at the central portion of its upper surface, while said upper link element is shaped in the form of an elongated plate adapted to cover the upper surface of said lower element, said upper link element having a pair of projections which enter into said opening of said lower link element; that spring means are enclosed within said lower link element and engage with said projections of said upper link element, so as to exert a force against each upper nd lower link element to tend to swing them on said connection to bring them into substantial alignment; and that said projections are formed on the central portions of the elongated edges o the upper link element and the elongated sides of the lower link element are cut away at their respective portions corresponding to said projections of said upper link element.
 2. An expansible linkage as defined in Claim 1, in which said spring means comprises a pair of substantially U-shaped wire members, one end of each of said wire members being engaged with and retained by one of said projections of said upper link element while the other end thereof bears against the side of said lower link element.
 3. An expansible linkage as defined in claim 2, in which each of said projections of said upper link element has a lateral extension at its free end.
 4. An expansible linkage as defined in Claim 1, in which said spring means comprises a pair of substantially arch-shaped wire members which engage at their respective apex portions with said projections of said upper link element. 